JP6860716B1 - Circular magnetic material for noise suppression - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an annular magnetic material for noise suppression showing high impedance regardless of whether a noise current is large or small. SOLUTION: The first annular magnetic body 10 and a second cyclic magnetic body 20 arranged concentrically with the first cyclic magnetic body 10 inside the first cyclic magnetic body 10 are included. , A noise-preventing annular magnetic material 100 used by inserting a cable inside the second annular magnetic material 20, wherein the first annular magnetic material 10 is a material having a superimposed magnetic field of 0 A / m and a frequency of 100 kHz. The impedance of the second annular magnetic material 20 is 20 Ω / mm or more, and the material impedance of the second annular magnetic material 20 at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz is 10 Ω / mm or more. [Selection diagram] Fig. 1

Description

The present invention relates to an annular magnetic material for noise suppression.

Conventionally, an annular magnetic material for noise suppression used by inserting a cable in order to reduce a noise current propagating in a cable connected to an electronic device has been known. In recent years, the output of electronic devices such as inverters and motors has increased. Further, the inverter has changed from a conventional inverter using a Si-IGBT to an inverter using a SiC-MOSFET capable of high-efficiency and high-speed switching. Therefore, there is a possibility that a large noise current may be generated in these electronic devices, and measures against the large noise current are desired.

A material having a high magnetic permeability is used for the soft magnetic material used for the annular magnetic material for noise suppression in order to effectively reduce the noise current. According to a material having a high magnetic permeability, a high noise suppression effect can be obtained when the noise current is small. However, in a material having a high magnetic permeability, the impedance decreases as the applied magnetic field increases, so-called magnetic saturation occurs, and the noise suppression effect decreases when the applied magnetic field is large. As the noise current increases, the magnetic field applied to the annular magnetic material for noise suppression also increases. Therefore, in order to effectively reduce a large noise current, a ring-shaped magnetic material for noise countermeasures is required, which is less likely to be magnetically saturated, that is, the impedance is less likely to decrease even when the applied magnetic field is increased. In the following, the property that the impedance is hard to decrease even if the applied magnetic field becomes large is also referred to as being excellent in DC superimposition characteristics.

Conventionally, by using a combination of magnetic materials having different magnetic characteristics, the noise suppression effect of the annular magnetic material for noise suppression is improved. Patent Document 1 proposes a composite toroidal core for a common mode choke in which magnetic materials having different frequency characteristics of magnetic permeability are arranged concentrically adjacent to each other. Since the magnetic flux density becomes higher toward the inside of the core, it is said that the saturation magnetic flux density of the material can be utilized to the maximum extent by arranging the core materials from the inside to the outside in order of increasing saturation magnetic flux density. Further, Patent Document 2 discloses a magnetic core for a choke coil in which a nanocrystal high magnetic permeability closed circuit magnetic core and a magnetic core having a gap or a powder magnetic core are integrated.

Japanese Unexamined Patent Publication No. 4-318906 Japanese Unexamined Patent Publication No. 7-153613

However, since the high saturation magnetic flux density and the superiority or inferiority of the DC superimposition characteristic do not always match, the cyclic magnetic materials are simply arranged from the inside to the outside in the order of the high saturation magnetic flux density as in the technique described in Patent Document 1. If only this is done, the DC superimposition characteristic of the annular magnetic material for noise suppression as a whole deteriorates, and there is a possibility that a sufficiently high noise suppression effect cannot be obtained when the noise current is large. Further, with respect to the technique described in Patent Document 2, since the magnetic core having a gap and the powder magnetic core have very low magnetic permeability, the annular magnetic material for noise suppression composed of these magnetic cores has a very high noise suppressing effect. Low is also a problem.

Therefore, an object of the present invention is to provide an annular magnetic material for noise suppression that exhibits high impedance regardless of whether the noise current is large or small.

The gist structure of the present invention is as follows.
[1] The second annular magnetic material includes a first annular magnetic material and a second cyclic magnetic material arranged concentrically with the first cyclic magnetic material inside the first cyclic magnetic material. It is a ring-shaped magnetic material for noise suppression that is used by inserting a cable inside the ring-shaped magnetic material of.
The first annular magnetic material has a superposed magnetic field of 0 A / m and a material impedance of 20 Ω / mm or more at a frequency of 100 kHz.
The second annular magnetic material is a noise countermeasure annular magnetic material having a superimposed magnetic field of 10 A / m and a material impedance of 10 Ω / mm or more at a frequency of 100 kHz.

[2] The annular magnetic material for noise suppression according to the above [1], wherein the first annular magnetic material has a superimposed magnetic field of 0 A / m and a material impedance of 25 Ω / mm or more at a frequency of 100 kHz.

[3] The annular magnetic material for noise suppression according to the above [1] or [2], wherein the second annular magnetic material has a superimposed magnetic field of 10 A / m and a material impedance of 15 Ω / mm or more at a frequency of 100 kHz. ..

[4] The noise according to any one of [1] to [3] above, wherein the second annular magnetic material has a superimposed magnetic field of 20 A / m and a material impedance of 5 Ω / mm or more at a frequency of 100 kHz. Circular magnetic material for countermeasures.

[5] The noise-preventing cyclic magnetic material according to any one of [1] to [4], which contains 20% by volume or more of the first cyclic magnetic material and the second cyclic magnetic material, respectively.

[6] The first annular magnetic material and the second annular magnetic material are any one of the above [1] to [5], each of which is composed of a plurality of parts divided in parallel in the central axis direction. The annular magnetic material for noise suppression described in the section.

According to the present invention, it is possible to provide an annular magnetic material for noise suppression that exhibits high impedance regardless of whether the noise current is large or small.

It is a figure which shows the outline of the annular magnetic material for noise countermeasures. It is a figure which shows the relationship between the superposed magnetic field and material impedance in Example 1 and Comparative Example 1.

Hereinafter, the present invention will be specifically described. In the present specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.

The annular magnetic material for noise suppression according to the present invention is
The second annular magnetism includes a first annular magnetic material and a second annular magnetic material concentrically arranged with the first annular magnetic material inside the first annular magnetic material. It is a ring-shaped magnetic material for noise suppression that is used by inserting a cable inside the body.
The first annular magnetic material has a superposed magnetic field of 0 A / m and a material impedance of 20 Ω / mm or more at a frequency of 100 kHz.
The second annular magnetic material is a noise countermeasure annular magnetic material having a superimposed magnetic field of 10 A / m and a material impedance of 10 Ω / mm or more at a frequency of 100 kHz.

Here, the material impedance is a single shape factor (mm) which is a value obtained by dividing the effective cross-sectional area Ae (mm ² ) of the test material by the average magnetic path length Lm (mm) of the test material. It refers to the value obtained by dividing the impedance (Ω) of the test material made of magnetic material. The material impedance is an index for evaluating the material-specific impedance that does not depend on the size of the test material.

The impedances of the annular magnetic material for noise suppression and the first and second annular magnetic materials are measured under the following conditions.
-Measuring device: Keysight 4990A
-Measurement frequency: 100 kHz
・ OSC current: 20mA
・ DC current: 0-100mA
-Number of turns: 30 turns The obtained impedance (Ω) is divided by the shape factor (mm) of each annular magnetic material to obtain the material impedance (Ω / mm).

Further, in the present invention, exhibiting high impedance even when the noise current is large, that is, excellent in DC superimposition characteristics means that the material impedance at a superimposition magnetic field of 10 A / m and a frequency of 100 kHz is 10 Ω / mm or more. Further, showing a high impedance even when the noise current is small means that the material impedance at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz is 20 Ω / mm or more.

FIG. 1 shows an outline of an annular magnetic material for noise suppression according to an embodiment of the present invention. As shown in FIG. 1, the noise countermeasure annular magnetic material 100 according to the present embodiment includes the first annular magnetic material 10 and the first annular magnetic material 10 inside the first annular magnetic material 10. Includes a second annular magnetic material 20 arranged concentrically. The first annular magnetic material 10 has a material impedance of 20 Ω / mm or more at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz. The second annular magnetic material 20 has a material impedance of 10 Ω / mm or more at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz. A cable connected to an electronic device, an electronic component, or the like is inserted into the hollow portion 30 in which the inner circumference of the second annular magnetic body 20 is partitioned.

In the noise countermeasure annular magnetic material 100 of the present embodiment, the first annular magnetic material 10 having a superimposed magnetic field of 0 A / m and a frequency of 100 kHz and a material impedance of 20 Ω / mm or more is arranged on the outside, and inside. By arranging the second annular magnetic material 20 having a material impedance of 10 Ω / mm or more at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz, high impedance can be obtained regardless of whether the noise current is large or small.

The magnetic field H (A / m) generated at a specific position of the noise countermeasure annular magnetic body 100 when a cable is inserted through the noise countermeasure annular magnetic body 100 and a current is passed causes the current flowing through the cable to be i (A). ), Assuming that the distance from the current at that position is r (m) and the number of turns of the cable with respect to the annular magnetic material 100 for noise suppression is n, according to Ampere's law
H = ni / (2πr)
Will be. That is, the magnetic field H at a specific position in the noise countermeasure annular magnetic body 100 is inversely proportional to the distance r from the current. That is, since a larger magnetic field is generated inside the noise countermeasure annular magnetic body 100, a high impedance is maintained when the noise current is large by using the second annular magnetic body 20 having excellent DC superimposition characteristics inside. can do. On the other hand, since the magnetic field is smaller toward the outside of the core, even the first annular magnetic material 10 having a high magnetic permeability, which is inferior in DC superimposition characteristics on the outside, can maintain a high impedance when the noise current is large. Further, when the noise current is small, a high impedance can be obtained due to the high magnetic permeability of the first annular magnetic material 10, and a high noise suppression effect can be expected. That is, according to the present embodiment, the material impedance at a superposed magnetic field of 10 A / m and a frequency of 100 kHz is 10 Ω / mm or more, and the material impedance at a superposed magnetic field of 0 A / m and a frequency of 100 kHz is 20 Ω / mm or more. A certain annular magnetic material 100 for noise suppression can be provided. The material impedance of the second annular magnetic material 20 at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz is preferably 15 Ω / mm or more. The material impedance of the first annular magnetic material 10 at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz is preferably 25 Ω / mm or more.

Conversely, an annular magnetic material with a superposed magnetic field of 0 A / m on the inside and a material impedance of 20 Ω / mm or more at a frequency of 100 kHz, and a ring with a material impedance of 10 Ω / mm or more on the outside of 10 A / m and a frequency of 100 kHz. If the arrangement is reversed as a magnetic material, each annular magnetic material cannot be used in an environment where the noise current can be effectively reduced, and the noise suppression effect of the noise countermeasure annular magnetic material 100 becomes small. Become. Further, when the first annular magnetic material 10 and the second annular magnetic material 20 are arranged side by side in series instead of being arranged concentrically, the first annular magnetic material 10 having a high magnetic permeability is inside with a large magnetic field. The magnetic permeability decreases. On the other hand, the second annular magnetic material 20 having excellent DC superimposition characteristics cannot effectively utilize the high DC superimposition characteristics on the outside where the magnetic field is small, and the low magnetic permeability of the entire annular magnetic material 100 for noise suppression It adversely affects the noise suppression effect. Therefore, the noise suppression effect of the annular magnetic material 100 for noise suppression as a whole is reduced. Therefore, by arranging the first annular magnetic material 10 having high magnetic permeability on the outside and the second annular magnetic material 20 having excellent DC superimposition characteristics on the inside so as to be concentric, regardless of whether the noise current is large or small. , Excellent noise suppression effect can be exhibited.

Further, in the present embodiment, a magnetic core having a gap formed as in Patent Document 2 described above is not required. Therefore, unlike Patent Document 2, there is no possibility that the cost will increase due to the formation of a gap in the magnetic core. Further, the gap-formed magnetic core and dust core used in Patent Document 2 described above have a problem that they are weak in terms of strength against external forces such as vibration. On the other hand, in the present embodiment, since the magnetic core having a gap and the powder magnetic core are not required, there is no problem in terms of strength.

The first annular magnetic material 10 arranged on the outer side in the radial direction has a material impedance of 20 Ω / mm or more at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz. When the superimposed magnetic field is 0 A / m and the material impedance at a frequency of 100 kHz is less than 20 Ω / mm, the noise suppression effect when the noise current is small becomes small. Therefore, it is necessary to increase the size of the annular magnetic material in order to obtain the necessary noise suppression effect, which causes a problem that the space for accommodating the noise countermeasure annular magnetic material 100 is expanded, and the weight of the noise countermeasure annular magnetic material 100. There arises a problem that the amount of noise increases and a problem that the manufacturing cost of the annular magnetic material 100 for noise suppression increases. The first cyclic magnetic material more preferably has a material impedance of 25 Ω / mm or more at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz. The upper limit of the material impedance when the superimposed magnetic field of the first annular magnetic material 10 is 0 A / m and the frequency is 100 kHz is not particularly limited, but is preferably 50 Ω / mm or less.

The first cyclic magnetic material 10 is made of a single magnetic material. Here, the single magnetic material refers to a material obtained by subjecting a material having the same composition to the same treatment. The first annular magnetic material 10 is preferably made of a soft magnetic material having a small coercive force and a high magnetic permeability. Examples of the soft magnetic material include ferrites such as Mn-Zn-based ferrite, Ni-Zn-based ferrite, and Ni-Zn-Cu-based ferrite; Fe-Ni-based alloy (Permalloy), Fe-Si-based alloy (silicon iron), and the like. Soft magnetic metals; Amorphous alloys such as Co-based amorphous alloys and Fe-based amorphous alloys; and Fe-based nanocrystalline alloys and the like can be used. Among the soft magnetic materials, the first cyclic magnetic material 10 is more preferably composed of an Fe—Ni based alloy (permalloy) and an Fe-based nanocrystal alloy. If the first annular magnetic body 10 constituting the Fe-based nanocrystalline alloys, for example, the general _{formula: (Fe 1-a M a} ) 100-xyzbcd A x M 'y M "z X b Si c B d ( atomic %) (In the formula, M is at least one element selected from Co and Ni, A is at least one element selected from Cu and Au, and M'is Ti, V, Zr, Nb, Mo, Hf. , At least one element selected from Ta and W, M ”is at least one element selected from Cr, Mn, Sn, Zn, Ag, In, white metal element, Mg, N and S, X is It represents at least one element selected from C, Ge, Ga, Al and P, where a, x, y, z, b, c and d are 0 ≤ a ≤ 0.1, 0.1 ≤ x ≤ 3, 1 ≤, respectively. Fe-based nanocrystal alloys having the general formula represented by (y ≦ 10, 0 ≦ z ≦ 10, 0 ≦ b ≦ 10, 11 ≦ c ≦ 17, 3 ≦ d ≦ 10) are particularly preferable. .. The composition of the Fe-based nanocrystal alloy is not particularly limited, but in terms of atomic%, Cu: 0.5 to 2.0%, Nb: 1.0 to 5.0%, Si: 11.0 to 15. It is preferable that the composition is 0%, B: 5.0 to 10.0%, and the balance is substantially Fe.

The method for producing the first cyclic magnetic material 10 is not particularly limited, and the first cyclic magnetic material 10 can be produced according to a known production method for the cyclic magnetic material. For example, a thin band-shaped amorphous alloy having a thickness of 5 to 50 μm is obtained from a molten alloy by a single roll method or the like, and the thin band-shaped amorphous alloy is wound in a cylindrical shape at a temperature of 300 ° C. or higher and 700 ° C. or lower. The first cyclic magnetic material 10 can be obtained by heat treatment for 5 to 20 minutes.

The second annular magnetic material 20 arranged inside has a material impedance of 10 Ω / mm or more at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz. If the material impedance at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz is lower than this, the noise suppression effect becomes small with respect to a large applied magnetic field, and sufficient noise suppression is not exhibited when a large noise current flows. More preferably, the material impedance at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz is 15 Ω / mm or more. When the noise current is large and the applied superposed magnetic field is large, the soft magnetic material used inside is further one having a superposed magnetic field of 20 A / m and a material impedance of 5 Ω / mm or more at a frequency of 100 kHz. preferable. The upper limit of the material impedance when the superimposed magnetic field of the second annular magnetic body 20 is 10 A / m and the frequency is 100 kHz is not particularly limited, but is preferably 30 Ω / mm or less.

The second cyclic magnetic material 20 is made of a single magnetic material different from the magnetic material constituting the first cyclic magnetic material 10. The second annular magnetic material 20 is preferably made of a soft magnetic material having a small coercive force and a high magnetic permeability. Examples of the soft magnetic material include ferrites such as Mn-Zn-based ferrite, Ni-Zn-based ferrite, and Ni-Zn-Cu-based ferrite; Fe-Ni-based alloy (Permalloy), Fe-Si-based alloy (silicon iron), and the like. Soft magnetic metals; Amorphous alloys such as Co-based amorphous alloys and Fe-based amorphous alloys; and Fe-based nanocrystalline alloys and the like can be used. Among the soft magnetic materials, the second cyclic magnetic material 20 is more preferably composed of an Fe-based nanocrystal alloy. As the Fe-based nanocrystal alloy, an Fe-based nanocrystal alloy in which the square ratio is reduced by heat treatment while applying a magnetic field is particularly effective, but this is not the case as long as it is excellent in DC superimposition characteristics. If the second annular magnetic body 20 constituting the Fe-based nanocrystalline alloys, for example, the general _{formula: (Fe 1-a M a} ) 100-xyzbcd A x M 'y M "z X b Si c B d ( atomic %) (In the formula, M is at least one element selected from Co and Ni, A is at least one element selected from Cu and Au, and M'is Ti, V, Zr, Nb, Mo, Hf. , At least one element selected from Ta and W, M ”is at least one element selected from Cr, Mn, Sn, Zn, Ag, In, white metal element, Mg, N and S, X is It represents at least one element selected from C, Ge, Ga, Al and P, where a, x, y, z, b, c and d are 0 ≤ a ≤ 0.1, 0.1 ≤ x ≤ 3, 1 ≤, respectively. Fe-based nanocrystal alloys having the general formula represented by (y ≦ 10, 0 ≦ z ≦ 10, 0 ≦ b ≦ 10, 11 ≦ c ≦ 17, 3 ≦ d ≦ 10) are particularly preferable. .. The composition of the Fe-based nanocrystal alloy is not particularly limited, but in terms of atomic%, Cu: 0.5 to 2.0%, Nb: 1.0 to 5.0%, Si: 11.0 to 15. It is preferable that the composition is 0%, B: 5.0 to 10.0%, and the balance is substantially Fe.

The method for producing the second cyclic magnetic material 20 is not particularly limited, and the second cyclic magnetic material 20 can be produced according to a known production method for the cyclic magnetic material. For example, a thin strip-shaped amorphous alloy having a thickness of 5 to 50 μm is obtained from a molten alloy by a single roll method or the like, and the thin strip-shaped amorphous alloy is wound in a cylindrical shape at a temperature of 300 ° C. or higher and 700 ° C. or lower. The second annular magnetic material 20 can be obtained by heat-treating for 5 to 20 minutes while applying a magnetic field of 80 kA / m or more in the height direction or the radial direction of the cylinder.

The volume% of the first annular magnetic material 10 and the second annular magnetic material 20 with respect to the entire noise countermeasure annular magnetic material 100 can be appropriately adjusted. Increasing the volume% of the first annular magnetic material 10 increases the impedance when the noise current is low. On the other hand, if the volume% of the second annular magnetic material 20 is increased, the impedance when the noise current is large can be increased. It is preferable that the first cyclic magnetic material 10 and the second cyclic magnetic material 20 are both 20% by volume or more. In other words, the upper limit of the volume% of the first cyclic magnetic material 10 and the second cyclic magnetic material 20 is preferably 80% by volume or less. If at least one of the first annular magnetic material 10 and the second annular magnetic material 20 is less than 20% by volume, a sufficient noise suppression effect can be obtained when these are combined to form the noise countermeasure annular magnetic material 100. I can't. More preferably, the first cyclic magnetic material 10 and the second cyclic magnetic material 20 are both 30% by volume or more.

The ring-shaped magnetic material 100 for noise suppression of the present embodiment is attached to cables of electronic components, power generation devices, power supply devices, communication devices, OA / FA devices, etc. provided in an automobile, and these electronic components and the inside of the electronic devices are attached. It is particularly effective as a ring-shaped magnetic material for noise suppression that suppresses noise generated in the cable or generated outside and propagated in the cable. When the noise countermeasure annular magnetic material 100 is used in these applications, the thickness of the cable through which the noise countermeasure annular magnetic material 100 is inserted may be 5 mm or more and 50 mm or less. Therefore, it is preferable that the inner diameter of the second annular magnetic material 20 is 6 mm or more and 155 mm or less so that the cable can be inserted. A plurality of cables may be inserted through the annular magnetic material 100 for noise suppression. The outer diameter of the second annular magnetic material 20 is preferably 10 mm or more and 230 mm or less so that sufficient DC superimposition characteristics can be obtained. Further, the first annular magnetic material 10 preferably has an inner diameter of 10.5 mm or more and 230.5 mm or less so that the second annular magnetic material 20 can be arranged inside. Further, the outer diameter of the first annular magnetic material 10 is preferably 14.5 mm or more and 250 mm or less in order to obtain a high noise suppression effect when the noise current is small. The dimensions (height) of the first annular magnetic body 10, the second annular magnetic body 20, and the noise countermeasure annular magnetic body 100 in the direction of the central axis of the ring are not particularly limited, but are, for example, 5 mm or more and 50 mm or less. Can be done.

In addition to the first cyclic magnetic material 10 and the second cyclic magnetic material 20, other cyclic magnetic materials may be provided. The other cyclic magnetic material may be provided concentrically with respect to the first cyclic magnetic material 10 and the second cyclic magnetic material 20. The other cyclic magnetic material may be provided inside the second annular magnetic material 20, or may be provided between the first cyclic magnetic material 10 and the second annular magnetic material 20. It may be provided outside the annular magnetic body 10 of 1. The other cyclic magnetic materials have, for example, a superposed magnetic field of 10 A / m and a material impedance at a frequency of 100 kHz in the order of superiority in comparison with the first cyclic magnetic material 10 and the second cyclic magnetic material 20. It is preferable to arrange the annular magnetic material from the inside to the outside of the noise countermeasure annular magnetic material 100 in descending order.

The gap between the first annular magnetic material 10, the second annular magnetic material 20, and the other cyclic magnetic material is preferably 0.25 mm or more and 5 mm or less. By setting the gap between these annular magnetic materials to 0.25 mm or more and 5 mm or less, it is easy to assemble the first annular magnetic material 10 and the second annular magnetic material 20, and there is little wasted space for noise suppression. The cyclic magnetic material 100 can be obtained.

The first annular magnetic material 10, the second annular magnetic material 20, and other cyclic magnetic materials that constitute the noise countermeasure annular magnetic material are adhered to each other so that the adjacent annular magnetic materials do not move with each other. , It is preferable that they are fixed to each other by a case, a band, or the like, but it is not necessary that the adjacent annular magnetic materials are completely adhered to each other. In order to integrate the first cyclic magnetic material 10, the second cyclic magnetic material 20, and other cyclic magnetic materials, these cyclic magnetic materials may be put together in a core case made of a resin or an elastomer. , The periphery of these cyclic magnetic materials may be coated with a resin, or an insulating tape may be wrapped around these cyclic magnetic materials. Each cyclic magnetic material may be impregnated with a resin, if necessary.

Further, the first annular magnetic body 10 and the second annular magnetic body 20 may each be composed of a plurality of parts divided in parallel in the central axis direction. Here, the central axis direction refers to a direction on a straight line extending perpendicularly to the radial direction from the center of the first annular magnetic body 10 and the second annular magnetic body 20. The number and size of the parts constituting the first annular magnetic material 10 and the second annular magnetic material 20 are not particularly limited. Further, each annular magnetic material may be divided in any way as long as it is parallel to the central axis direction. For example, each part may have a shape in which each annular magnetic material is divided along the radial direction. According to this configuration, the noise-preventing annular magnetic material 100 can be inserted into the cable even when the cable is wired to an electronic device, an electronic component, or the like. Can be installed more easily. When the noise countermeasure annular magnetic material 100 has another annular magnetic material, it is preferable that the other annular magnetic material is also composed of a plurality of parts divided in parallel in the central axis direction.

The operating frequency of the noise countermeasure annular magnetic material 100 is not limited to 100 kHz, and can be used in a wide range of frequencies. The noise countermeasure annular magnetic material 100 can be used, for example, at a frequency of 10 kHz or more and 1000 kHz or less. Even if the ring-shaped magnetic material for noise suppression is used at a frequency other than 100 kHz, the technical aspect of the present invention is as long as the superimposed magnetic field and material impedance values when measured at a frequency of 100 kHz are within the range of the present invention. Included in the range.

Hereinafter, the present embodiment will be described according to the examples, but the present embodiment is not limited to these examples.

(Example 1)
As shown in FIG. 1, a noise countermeasure annular magnetic material composed of two types of cyclic magnetic materials, a first cyclic magnetic material and a second cyclic magnetic material, was produced. First, the first cyclic magnetic material was produced by the following procedure. In terms of atomic%, Cu: 1%, Nb: 3%, Si: 13.5%, B: 9%, and the remaining alloy is rapidly cooled by the single roll method to a thickness of 15 mm. A thin strip-shaped amorphous alloy having a size of 20 μm was obtained. The amorphous alloy was wound around a cylinder having an outer diameter of 41 mm to form a cylinder having an inner diameter of 41 mm and an outer diameter of 50 mm. The cylindrical amorphous alloy was inserted into a heat treatment furnace kept at 550 ° C. under an argon atmosphere and heat-treated for 10 minutes. Then, a cylindrical first annular magnetic material having an inner diameter of 41 mm, an outer diameter of 50 mm, and a height of 15 mm, made of a high magnetic permeability nanocrystal material, was obtained. Moreover, the second cyclic magnetic material was produced by the following procedure. First, an amorphous alloy was obtained in the same manner as the first cyclic magnetic material. The amorphous alloy was wound into a cylindrical shape having an outer diameter of 40 mm and an inner diameter of 30 mm. Then, the cylindrical amorphous alloy was inserted into a heat treatment furnace kept at 550 ° C. under an argon atmosphere. The heat treatment was performed for 10 minutes while applying a magnetic field of 280 kA / m in the height direction of the amorphous alloy cylinder. Then, a second cyclic magnetic material made of a highly saturated nanocrystal material was obtained. Next, a second annular magnetic material is arranged inside the first annular magnetic material, and the circumference is wrapped with insulating tape to fix the first annular magnetic material and the second annular magnetic material for noise suppression. A cyclic magnetic material was obtained. According to the method described above, the material impedance of the first annular magnetic material at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz, and the material impedance of the second annular magnetic material at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz were measured. Further, the material impedance of the annular magnetic material for noise suppression at a frequency of 100 kHz was measured while changing the superimposed magnetic field from 0 A / m to 20 A / m. The results are shown in Table 1. In addition, the material impedance obtained for the annular magnetic material for noise suppression was plotted on a graph with the horizontal axis as the superimposed magnetic field and the vertical axis as the material impedance. The results are shown in FIG.

(Example 2)
A noise-preventing annular magnetic material was produced in the same manner as in Example 1 except that the thin band-shaped amorphous alloy used for producing the second annular magnetic material had a width of 15 mm and a thickness of 15 μm. The material impedance of the second annular magnetic material at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz, and the material impedance of the annular magnetic material for noise suppression at a frequency of 100 kHz were measured according to the method described above. The results are shown in Table 1.

(Comparative Example 1)
The materials of the first cyclic magnetic material and the second cyclic magnetic material are exchanged, that is, the first cyclic magnetic material is composed of a highly saturated nanocrystal material, and the second cyclic magnetic material is a high magnetic permeability nanocrystal material. An annular magnetic material for noise suppression was produced in the same manner as in Example 1 except that the material was composed of. According to the method described above, the material impedance of the first annular magnetic material at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz, and the material impedance of the second annular magnetic material at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz were measured. Further, according to the method described above, the material impedance of the obtained annular magnetic material for noise suppression at 100 kHz was measured while changing the superimposed magnetic field from 0 A / m to 20 A / m. The results are shown in Table 1. In addition, the material impedance obtained for the annular magnetic material for noise suppression was plotted on a graph with the horizontal axis as the superimposed magnetic field and the vertical axis as the material impedance. The results are shown in FIG.

(Comparative Example 2)
The thin band-shaped amorphous alloy obtained in the same manner as the first annular magnetic material of Example 1 is wound around a cylinder having an outer diameter of 30 mm to form a cylindrical shape having an inner diameter of 30 mm and an outer diameter of 50 mm. The same heat treatment as that of the annular magnetic material of No. 1 was performed to obtain a ring-shaped magnetic material for noise suppression of Comparative Example 2 having an outer diameter of 50 mm, an inner diameter of 30 mm, and a height of 15 mm without being combined with the second annular magnetic material. According to the method described above, the material impedance of the obtained annular magnetic material for noise suppression at 100 kHz was measured while changing the superimposed magnetic field from 0 A / m to 20 A / m. The results are shown in Table 1.

(Comparative Example 3)
The thin band-shaped amorphous alloy obtained in the same manner as the second annular magnetic material of Example 1 was wound around a cylinder having an outer diameter of 30 mm to form a cylindrical shape having an inner diameter of 30 mm and an outer diameter of 50 mm. Next, the cylindrical amorphous alloy was heat-treated while applying a magnetic field under the same conditions as the second annular magnetic material of Example 1, and the outer diameter was 50 mm and the inner diameter was 50 mm without being combined with the first annular magnetic material. The annular magnetic material for noise suppression of Comparative Example 3 having a height of 30 mm and a height of 15 mm was used. The material impedance of the obtained annular magnetic material for noise suppression at 100 kHz was measured while changing the superimposed magnetic field from 0 A / m to 20 A / m. The results are shown in Table 1.

(Comparative Example 4)
A ring-shaped magnetic material for noise suppression was produced in the same manner as in Example 1 except that the second cyclic magnetic material was changed to a nanocrystal material with a gap. The nanocrystal material with a gap was produced by the following procedure. First, a thin band-shaped amorphous alloy similar to the second annular magnetic material of Example 1 is wound around a cylinder having an outer diameter of 30 mm to form a cylindrical shape having an inner diameter of 30 mm and an outer diameter of 40 mm, and then 550 under an argon atmosphere. It was inserted into a heat treatment furnace kept at ° C. and heat-treated for 10 minutes without applying a magnetic field to obtain a cylindrical annular magnetic material. Then, the cyclic magnetic material was immersed in the epoxy resin for 10 minutes and then taken out, and after removing the excess resin, it was held at 80 ° C. for 3 hours to solidify. Then, a grindstone having a thickness of 1 mm was used to make one cut along the height direction of the cylinder to obtain a nanocrystal material with a gap having an outer diameter of 40 mm, an inner diameter of 30 mm, and a height of 15 mm. The obtained nanocrystal material with a gap was fixed to the first cyclic magnetic material in the same manner as in Example 1 to obtain a cyclic magnetic material for noise suppression. According to the method described above, the material impedance of the second annular magnetic material at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz was measured. Further, according to the method described above, the material impedance of the obtained annular magnetic material for noise suppression at 100 kHz was measured while changing the superimposed magnetic field from 0 A / m to 20 A / m. The results are shown in Table 1.

(Comparative Example 5)
A ring-shaped magnetic material for noise suppression was produced in the same manner as in Example 1 except that the second cyclic magnetic material of Example 1 was changed to a nanocrystal dust core. The nanocrystal dust core was manufactured by the following procedure. The amorphous alloy used to prepare the second cyclic magnetic material in Example 1 was pulverized into a powder. Next, after mixing the powder with a binder (polyimide), a pressure of 800 MPa is applied to form a cylindrical shape having an outer diameter of 40 mm and an inner diameter of 30 mm, which is fired at a maximum temperature of 550 ° C. without applying a magnetic field. A cyclic magnetic material was obtained. According to the method described above, the material impedance of the second annular magnetic material at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz was measured. Further, according to the method described above, the material impedance of the obtained annular magnetic material for noise suppression at 100 kHz was measured while changing the superimposed magnetic field from 0 A / m to 20 A / m. The results are shown in Table 1.

The relationship between the superimposed magnetic field and the material impedance at 100 kHz in Example 1 and Comparative Example 1 is shown in FIG. As is clear from FIG. 2, in Comparative Example 1, the material impedance is high when the superposed magnetic field is 0 A / m, but since the high magnetic permeability nanocrystal material is inside, the material impedance increases as the superposed magnetic field increases. It drops sharply. On the other hand, in Example 1, since a highly saturated nanocrystal material is used inside, the superimposed magnetic field is 10 A while showing a high material impedance of 20 Ω / mm or more even when the superimposed magnetic field is 0 A / m. The material impedance maintains a high value of 10 Ω / mm or more even at / m, and a high noise suppression effect is exhibited regardless of whether the noise current is large or small.

In Example 2, a highly saturated nanocrystal material having a higher magnetic permeability than that of Example 1 is used as the second cyclic magnetic material. Therefore, while maintaining a high material impedance of 10 Ω / mm or more when the superposed magnetic field is 10 A / m, the material impedance when the superposed magnetic field is 0 A / m is increased to 25 Ω / mm or more.

Comparative Examples 2 and 3 are cases where only one type of each of the first cyclic magnetic material and the second cyclic magnetic material of Example 1 is used. When the annular magnetic material for noise suppression is composed only of the first annular magnetic material which is a high magnetic permeability nanocrystal material, the material impedance when the superimposed magnetic field is 0 A / m is as high as 25 Ω / mm or more. However, when the superimposed magnetic field is 10 A / m, the material impedance becomes less than 10 Ω / mm, and when the noise current is large, the noise suppression effect is reduced. Further, when the annular magnetic material for noise suppression is composed only of the second annular magnetic material which is a highly saturated nanocrystal material, the material impedance when the superimposed magnetic field is 10 A / m takes a high value of 15 Ω / mm or more. However, when the superimposed magnetic field is 0 A / m, the material impedance is less than 20 Ω / mm, and conversely, when the noise current is small, the noise suppression effect is reduced.

When a nanocrystal material with a gap or a nanocrystal dust core having excellent DC superimposition characteristics is used as the second cyclic magnetic material as in Comparative Examples 4 and 5, the material impedance is superposed because their magnetic permeability is too low. The magnetic field becomes low over the entire range of 0 A / m to 20 A / m, and the noise suppression effect is greatly reduced.

(Examples 3 to 6)
In the combination of the first cyclic magnetic material and the second cyclic magnetic material of Example 1, the volume fraction of each cyclic magnetic material was changed, and changes in material impedance and DC superimposition characteristics were investigated. Noise countermeasures in Examples 3 to 6 are the same as in Example 1 except that the volume fractions of the first cyclic magnetic material and the second cyclic magnetic material of Example 1 are changed as shown in Table 2. A ring-shaped magnetic material for use was prepared. The size of the annular magnetic material for noise suppression was 50 mm in outer diameter, 30 mm in inner diameter, and 15 mm in height. According to the method described above, the material impedance of the first annular magnetic material at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz, and the material impedance of the second annular magnetic material at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz were measured. Further, according to the method described above, the material impedance of the annular magnetic material for noise suppression at 100 kHz was measured. The results are shown in Table 2.

(Comparative Examples 6 to 7)
Comparative Examples 6 and 7 are examples in which the ratio of the first cyclic magnetic material or the second cyclic magnetic material is less than 20%, respectively. A noise-preventing cyclic magnetic material was produced in the same manner as in Example 1 except that the ratios of the first cyclic magnetic material and the second cyclic magnetic material were set to the values shown in Table 2. According to the method described above, the material impedance of the first annular magnetic material at a superimposed magnetic field of 0 A / m and a frequency of 100 kHz, and the material impedance of the second annular magnetic material at a superimposed magnetic field of 10 A / m and a frequency of 100 kHz were measured. Further, according to the method described above, the material impedance of the annular magnetic material for noise suppression at 100 kHz was measured. The results are shown in Table 2.

In Example 3, since the volume fraction of the second annular magnetic material is high, the material impedance when the superimposed magnetic field is 10 A / m is as high as 14.4 Ω / mm. On the contrary, in Example 6, since the volume fraction of the first annular magnetic material is high, the material impedance when the superimposed magnetic field is 0 A / m is as high as 23.3 Ω / mm. By adjusting the volume fractions of the first annular magnetic material and the second annular magnetic material to be used in this way, the balance between the DC superimposition characteristic and the material impedance when the noise current is small is adjusted, and the noise current is adjusted. An excellent noise suppression effect can be obtained regardless of whether the value is large or small.

Further, as is clear from the result of Comparative Example 6, when the ratio of the first cyclic magnetic material is small, the material impedance when the superimposed magnetic field is 0 A / m is less than 20 Ω / mm. On the other hand, as is clear from the results of Comparative Example 7, when the ratio of the second cyclic magnetic material is small, the material impedance when the superimposed magnetic field is 10 A / m is less than 10 Ω / mm. As described above, if the volume ratios of the first annular magnetic material and the second annular magnetic material are not 20% by volume or more, the balance between the DC superimposition characteristic and the material impedance when the noise current is small is lost, and noise occurs. When the current is large or small, the noise suppression effect becomes inferior.

From the above, it can be seen that Examples 1 to 6 of the present embodiment are noise-preventing annular magnetic materials that are excellent in DC superimposition characteristics and exhibit high impedance even when the noise current is small.

This ring-shaped magnetic material for noise suppression is attached to cables of electronic parts, power generation devices, power supply devices, communication devices, OA / FA devices, etc. provided in automobiles, and is generated inside these electronic parts and electronic devices. Alternatively, it is particularly effective as a ring-shaped magnetic material for noise suppression that suppresses noise generated outside and propagating in the cable.

100 Circular magnetic material for noise suppression 10 First annular magnetic material 20 Second annular magnetic material 30 Hollow part

Claims (6)

The second annular magnetism includes a first annular magnetic material and a second annular magnetic material concentrically arranged with the first annular magnetic material inside the first annular magnetic material. It is a ring-shaped magnetic material for noise suppression that is used by inserting a cable inside the body.
The first annular magnetic material has a superposed magnetic field of 0 A / m and a material impedance of 20 Ω / mm or more at a frequency of 100 kHz.
The second annular magnetic material is a noise countermeasure annular magnetic material having a superimposed magnetic field of 10 A / m and a material impedance of 10 Ω / mm or more at a frequency of 100 kHz. The annular magnetic material for noise suppression according to claim 1, wherein the first annular magnetic material has a superimposed magnetic field of 0 A / m and a material impedance of 25 Ω / mm or more at a frequency of 100 kHz. The noise-preventing annular magnetic material according to claim 1 or 2, wherein the second annular magnetic material has a superimposed magnetic field of 10 A / m and a material impedance of 15 Ω / mm or more at a frequency of 100 kHz. The noise-preventing annular magnetic material according to any one of claims 1 to 3, wherein the second annular magnetic material has a superimposed magnetic field of 20 A / m and a material impedance of 5 Ω / mm or more at a frequency of 100 kHz. The noise-preventing annular magnetic material according to any one of claims 1 to 4, which contains 20% by volume or more of the first annular magnetic material and the second annular magnetic material, respectively. The noise countermeasure according to any one of claims 1 to 5, wherein the first annular magnetic material and the second annular magnetic material are each composed of a plurality of parts divided in parallel in the central axis direction. Ring magnetic material for.

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